temperature not going above 120

[agaldamez]

just changed impeller and my temperature did not rise above 120.

I tested the gauge by detaching the tan wire from the water temperature sender and grounded it and the gauge went all the way to 240. so i am assuming the gauge is good. Should i change the water temperature sender.

 

[Don S]

Re: temperature not going above 120

Is the engine that cold? Check the temp with one of those IR temp guns, and check next to the temp sender. If it shows the same (or really close) to the same thing, then it's not a sender problem, you have an over cooling problem. Possibly a thermostat stuck open a little bit.

 

[agaldamez]

Re: temperature not going above 120

i am assuming that i could do this by flushing the engine. the open thermostat, what would be the danger of not doing something right away.

when i pulled the boat out the past weekend it seemed like a lot of water coming out of the engine from the lower gear and from above near the speedometer plug area.

could the thermostat be allowing to much water???

 

[cecho]

Re: temperature not going above 120

I've seen sticky thermostats stick closed, but what will most likely happen is your engine will run a tad bit too cool. A cool running engine will be less efficient and wear out a bit faster, but it won't cause any catastrophic harm. Check the temp with an IR gun first to rule out a bad sender, gauge or wiring. Every mechanic or cook should have one of these.

My engine was running a bit too cool as well a week ago (120). Then it started to run a bit warm (160 - 180) then snap back quickly to too cool (120) and stay there when I was last out. Eventually, a thermostat like that might just stay closed one day and overheat the engine... or it might stay completely open which will over cool the engine.

 

[agaldamez]

Re: temperature not going above 120

Will be trying this next couple of days.

 

[tazrig]

Re: temperature not going above 120

i am assuming that i could do this by flushing the engine. the open thermostat, what would be the danger of not doing something right away.

Nothing immediate but long term an engine running cooler than it should doesn't run as efficiently as it should and it also doesn't burn the condensation out the motor oil so the oil doesn't do it's job as well as it should.

 

[agaldamez]

Re: temperature not going above 120

Thanks don, ran boat and temperature was a dead on match. Changing thermostat on friday.
Thanks Again.

 

[agaldamez]

Re: temperature not going above 120

change thermostat ran engine after 10 minutes, temperature at 160, got up to 170. so i pretty sure thermostat was wide open and engine would never get over 120.

so i know that a good temperature is 160 for a 4.3 mercruiser, what is the hottest it should get.